Remove Yesod.Auth.OAuth2.Google.hs

This functionality is available in yesod-auth, in the
Yesod.Auth.GoogleEmail2 module.

Resolves #18

Yesod/Auth/OAuth2/Google.hs

@@ -1,30 +0,0 @@
-{-# LANGUAGE OverloadedStrings #-}
--- |
---
--- OAuth2 plugin for http://google.com
---
--- * Note: this module is unfinished, do not use.
---
-module Yesod.Auth.OAuth2.Google
-    ( oauth2Google
-    , module Yesod.Auth.OAuth2
-    ) where
-
-import Data.Text (Text)
-import Data.Text.Encoding (encodeUtf8)
-import Yesod.Auth
-import Yesod.Auth.OAuth2
-
-oauth2Google :: YesodAuth m
-             => Text -- ^ Client ID
-             -> Text -- ^ Client Secret
-             -> AuthPlugin m
-oauth2Google clientId clientSecret = authOAuth2 "google"
-    (OAuth2
-        { oauthClientId            = encodeUtf8 clientId
-        , oauthClientSecret        = encodeUtf8 clientSecret
-        , oauthOAuthorizeEndpoint  = "https://accounts.google.com/o/oauth2/auth"
-        , oauthAccessTokenEndpoint = "https://accounts.google.com/o/oauth2/token"
-        , oauthCallback            = Nothing
-        })
-    undefined -- TODO

yesod-auth-oauth2.cabal

@@ -45,7 +45,6 @@ library
                    , lifted-base             >= 0.2       && < 0.4
 
     exposed-modules: Yesod.Auth.OAuth2
-                     Yesod.Auth.OAuth2.Google
                      Yesod.Auth.OAuth2.Learn
                      Yesod.Auth.OAuth2.Github
                      Yesod.Auth.OAuth2.Spotify